Converting Percentages to GPA: Why There Is No Single Formula

If you have ever tried to turn a percentage grade into a GPA, you will have found a dozen conflicting tables and calculators online. That is because there is no single, official conversion. A percentage is a measure of your performance in one course, and a GPA is a scale used by a particular school or country. Each institution decides how percentages map to letter grades and grade points.

This guide explains how the conversion works, gives a common table as an example and shows how to find the right one for your situation.

Why there is no universal conversion

Several things make a universal formula impossible:

• Different grading cultures. In some systems, 70 percent is an excellent grade, while in others it is barely a pass.
• Different scales. Schools use 4.0, 4.3, 5.0, 9, 10 or 12-point scales, among others.
• Different cutoffs. One school's A may start at 90 percent, another's at 85 and another's at 80.
• Different meanings. A percentage can reflect a curve, a raw mark or a weighted average of assessments.

So a statement such as "85 percent is a 3.5 GPA" is true only under a specific table.

A common US-style table

Many US high schools and colleges use something like the following. It is an example, not a rule.

Other schools use simpler cutoffs, such as 90 for A, 80 for B, 70 for C and 60 for D, with no plus or minus. Look at your own syllabus, since individual instructors often set the cutoffs for their courses.

Find the right scale

Start with the source closest to your situation.

1. Your course syllabus. It usually states how percentages become letter grades.
2. Your school's registrar or catalog. The academic regulations list the official scale for transcripts.
3. The program you are applying to. Admissions pages sometimes state how they convert or which scale to report.
4. A credential evaluation service, if a program requires an evaluation of international grades.

Use the scale that the receiving institution uses, not a random online calculator.

Percent to letter to GPA, in two steps

Converting is a two-step process:

1. Turn the percentage into a letter grade using the cutoffs for the course or school.
2. Turn the letter grade into grade points using the school's scale.

Then use the grade points, with credit hours, to calculate GPA in the usual way. Our guide to how to calculate your GPA shows how.

Example

Suppose a course grade is 88 percent. Under the table above, that is a B-plus, which is 3.3 grade points. If the course is four credits, it contributes 13.2 quality points. If your school uses simpler cutoffs, 88 is a B, which is 3.0, and the course contributes 12.0. The same percentage produces a different GPA contribution under a different scale.

Percentages within a course

Percentages also appear inside a course, as the weighted average of assignments, exams and participation. Here the question is different: what percentage do I need on the final to reach a given grade? Our final grade calculator answers that, using the weights in your syllabus. Once you know your course percentage, you can use the scale above to see the letter grade.

When an application asks for a GPA you do not have

Many students from systems that use percentages, marks or class rankings face application forms that ask for GPA. The right approach is:

1. Read the instructions. Many programs say to report your grades as they appear on your transcript.
2. Enter your original grades, not an invented conversion, unless told otherwise.
3. Use the evaluation service if the program requires one.
4. Attach the grading scale or an explanation from your institution, which many schools provide.
5. Ask the admissions office if you are unsure.

Admissions offices are used to converting grades from many systems, and they have their own methods.

Why online converters can mislead

Online converters often present a single table as if it were universal. They may be built for one country or one school, and they may simply be wrong for yours. They can still be useful as a rough check, for example to estimate where you stand, but do not put a converted figure on a formal application unless you are told to. If you use one, note which scale it uses.

Special cases

• Weighted courses. High school honors and AP courses may add a point or fraction to grade points. See our guide on weighted vs unweighted grades.
• Curved grades. Your percentage may be adjusted by the instructor, so the letter grade can differ from the raw percentage.
• Rounding. Some courses round up at the boundary, and others do not. Check the syllabus.
• Rare grading systems. Some countries use a 20-point or 10-point scale, with very different norms for what counts as high.

Common mistakes

1. Assuming one table applies everywhere.
2. Using an online converter on a formal form.
3. Forgetting that instructors set their own cutoffs.
4. Converting twice, from percent to GPA to a different scale.
5. Ignoring rounding rules at boundaries.

Worked example: from a course percentage to a GPA contribution

Suppose you finish a four-credit course with an overall 91 percent. Under the common table in this guide, 91 falls in the A-minus range, which is 3.7 grade points. The course contributes 4 times 3.7, which is 14.8 quality points. If the same 91 had been a straight A at a school with cutoffs of 90 for an A, it would contribute 4 times 4.0, which is 16. The difference of 1.2 quality points may seem small, but across many courses it shapes the final GPA.

Why borderline marks need care

A mark close to a cutoff, such as 89.6, can be rounded up by some instructors and not by others. Some syllabi say that marks are rounded to the nearest whole number, others that they are not rounded at all. If you are within a point of a cutoff, ask politely about the policy early in the term, not after the grade is posted. Do not assume that rounding will happen.

Curving and its effect

In a curved course, your percentage is adjusted, or your letter grade is based on your rank in the class, not on fixed cutoffs. A curved A might correspond to 82 percent in a hard exam and 95 in an easy one. In that situation, a percentage conversion table tells you little. Ask the instructor whether grades are curved, and what the typical distribution looks like.

A final tip for students who move between systems: keep a copy of the grading scale that applied at each institution and in each year, since scales can change over time. When you later need to explain an old transcript, being able to show the scale in force at the time makes your explanation credible, and avoids disputes about what a particular mark meant when you earned it.

The bottom line

There is no universal formula for converting percentages to GPA. Use the table from your own school or the program you are applying to, convert in two steps and double-check with your syllabus and registrar. When an application asks for a GPA you do not have, report your grades as they appear and let the admissions office convert them.